1. Field of the Invention
The present invention generally relates to a plasma assisted apparatus for organic film deposition and, more particularly, to a plasma assisted apparatus capable of forming organic films at low temperatures using a plasma chamber and a deposition chamber being separated to prevent the substrate form being bombarded by plasma.
2. Description of the Prior Art
The organic light-emitting diode (OLED) display panel has a short lifetime because the organic layer tends to absorbing moisture in the air. As a result, the OLED device is not as competitive as the LCD device in the market. It is known that the lifetime of the OLED device can be prolonged by using a polymeric organic thin film with an inorganic thin film to prevent moisture from entering the OLED device.
Parylene can be used to form a pin-hole free film to exhibit excellent moisture resistance, colorlessness, high transparency, high dielectric strength, high resistance to rust, erosion and weathering. A parylene film is formed by vaporizing (at 150° C.) and cracking (at 650° C.) parylene powders and introducing the cracked products into a deposition chamber to perform chemical vapor-phase deposition (CVD) on the substrate surface at room temperature. However, this leads to non-uniformity and roughness on the thin film surface.
In U.S. Patent Publication No. 20050000435 “Reactor for producing reactive intermediates for low dielectric constant polymer films” and U.S. Pat. No. 5,958,510 “Method and apparatus for forming a thin polymer layer on an integrated circuit structure”, cracking is performed outside the deposition chamber and the chemical bonding is broken by plasma inside the deposition chamber to form low-dielectric organic films at a higher deposition rate. The organic films grown by such a method exhibit improved thermal mechanics characteristics but poor uniformity as well as roughness. It is also noted that plasma assisted deposition is performed on the substrate surface inside the deposition chamber. Therefore, the deposition temperature is high and the grown organic film has unreliable film quality and a short lifetime because the substrate is directly bombarded by plasma particles.